Premium
Resonance Raman spectroscopic study of the neutral flavin radical complex of DNA photolyase from Escherichia coli
Author(s) -
Murgida Daniel H.,
Schleicher Erik,
Bacher Adelbert,
Richter Gerald,
Hildebrandt Peter
Publication year - 2001
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.719
Subject(s) - flavin group , photolyase , chemistry , resonance raman spectroscopy , raman spectroscopy , photochemistry , cofactor , resonance (particle physics) , stereochemistry , dna , enzyme , dna repair , biochemistry , atomic physics , physics , optics
The neutral flavin radical complex of DNA photolyase from Escherichia coli was studied by resonance Raman spectroscopy for the first time. The experiments were carried out with enzyme variants that lack the light‐harvesting methenyltetrahydrofolate cofactor so that the resonance Raman spectra exclusively display the vibrational bands of the flavin radical in the catalytic site. Spectral changes induced upon H–D exchange and upon substituting the natural flavin by its 15 N‐labelled isotopomer allow a tentative assignment of the prominent bands in the region between 1200 and 1650 cm −1 . It is shown that most of the bands observed with 568 nm excitation originate from modes localized in the isoalloxazine ring. In conjunction with previous data on flavin radicals, the present results allow the identification of the marker bands that appear to be particularly sensitive towards changes in the electron density distribution of this ring and, hence, reflect the specific intermolecular interactions in the catalytic site. Copyright © 2001 John Wiley & Sons, Ltd.